An Ill-Engineered Alarm Clock Feature

Posted on by frankwmcarr

My alarm clock, just several years old, has a seemingly nifty feature that actually backfires.

This feature is essentially a projector of the time against a ceiling, to be used typically at night.  Imagine, time on your ceiling!

But, not so fast.  The projected time, by our perception it becomes blurred when viewed in the very milieu that it was made for:  a nighttime room!

So, what’s the secret?  Central vision works best in sufficiently bright light, due to its domination of cones.  On the other hand, vision in the dark is run by rod cells, which dwell outside that central region of the retina. So the point of the projected image your eyes are focused on is actually fuzzy.  Moreover, since only cones can process light info that contains color, they are disadvantaged in a dark room as such.  Of course, the alarm clock proper does not bear this difference, for this display, by its nature is its own light source.  And now that I have advised you of this sly feature, I hope you can get a better understanding of this.  (They probably should have consulted a neuroscientist, neurologist or ophthalmologist for better insight.  LOL)

And for the stargazers among you, this is true for dim stars, which can only be seen at a  directly adjacent point.

Alarm Projector
While there is apparently no difference in visibility in a camera, when your eyes actually this very image, you may have to “zig-zag” your gaze to get the time, or just use the commonsense method, look at the clock itself!

As a man blessed as a articulate writer and knowledge liaison, again and again you can count on me for making the arcane, technical world of science (and other topics) yours, especially after further schooling (and perhaps personal study of these secular topics).  And this may be a good time to focus my blog as I follow my Lord and Savior Jesus.

I must mention a key Scripture passage: the Parable of the Talents in Matthew 25, that whatever you’ve been given, you should appreciate, and indeed build upon that.  The word “talent” in that time, which was a very large monetary unit, has been adopted into English as what it means now:  a natural skill, honed by practice!  So don’t take your talents lightly.  The parable, as usual, is what Jesus spoke to the disciples.

So be a wise consumer.  Pray for what you need.  And remember, even the finest things earth has to offer is not even near perfect.

Ramadan, VCR Connection, and Vision

Posted on by frankwmcarr

Many of my Muslim readers, now in the throes of Ramadan, their holiest month when eating is prohibited daily from dawn to dusk, are probably really bent out of shape.  Their main test of when to cease eating each morning is by distinguishing a white thread from a black one.

As for me, one evening, had a similar battle when hooking up a digital-to-analog converter (using red-yellow-white A/V cable) to a VHS VCR, in turn to a analog TV.  The portion with the yellow plug is for video, that with the white plug is for audio.  The red plug, also for audio, was here irrelevant due to the monaural nature of this VCR (it would typically be used for stereo purposes).  So anyway, due to the A/V inputs (and outputs) being in a deep nook in the rear face of the VCR, without enough illumination, the yellow and white jacks were hardly distinguishable.

For this situation and the Ramadan test above, the same phenomenon is at play here.  Colors cannot be distinguished until light is bright enough.  Until that threshold is reached, the retinal rod cells all act the same way (though differently with different colors, I assume these are different shades of gray).  But with enough light, yellow and white are distinguishable, and ditto for the daily Ramadan thread test.

Hmm…maybe I should use a flashlight next time.  As for the early-morning “thread test” and the all-day fast throughout Ramadan, that makes me glad (personally at least) that I’m not a Muslim!

Why Owls Can Turn their Heads Toward their Backs

Posted on by frankwmcarr

Owls, aside from their folklore-based wisdom, bear one capacity that we humans can only dream of:  viewing what’s behind them without turning around.  Their heads can turn 270° from the frontal position, which is really just 90° in the opposite direction.

However, what really warrants this need is 1) their very large, almost motionless eyes, and 2) the arterial organization toward the brain.

In owls, the vertebrae give ample space in certain arteries, which in humans are confined to small spaces.  Also, the carotid artery, a “confined” artery, happens to be at the central axis of rotation.  And like humans, predatory birds, and animal able to hunt, their vision is binocular and thus with good depth perception.

These details and more, can be seen in the attached YouTube video below, courtesy of the principal source (at the bottom of the page, which you can also visit.  By the way, this observation was not primarily studied by ornithologists, but by medical doctors who specialize in vascular issues.  Their insight is highly appreciated.

 

With the eyeful they receive on a daily basis, no wonder they’re considered so “wise.”

Source:  people.eku.edu/ritchisong/birdbrain2.htm